阅读说明：本技术 一种焙烧氰化尾渣氯化挥发提金方法 (Method for extracting gold by chlorination and volatilization of roasted cyanidation tailings ) 是由 钱虎 邵京明 冯玉华 桑胜华 丁雨波 潘贵 迟正峰 刘春荣 孙磊 师超 温建爽 于 2019-10-16 设计创作，主要内容包括：本发明公开了一种焙烧氰化尾渣氯化挥发提金方法,选矿样,矿样来自金精焙烧-酸浸-氰化-脱水-干燥后的氰化尾渣,含水15.08%、金品位6.25g/t、银品位10.10g/t、硫含量1.6%、铁含量33%；在氰化尾渣中按比例加入氯化剂、水和粘结剂,混合均匀；采用压球机造球,温度为1000-1200℃,焙烧时间2h；经干燥箱干燥得生球,生球放置于马弗炉中于1100℃氧化性氛围高温焙烧2h；放入回转窑内,在800℃-1150℃-950℃连续升温、降温的情况下焙烧150min；降温冷却后测定金、银含量。本发明所述焙烧氰化尾渣氯化挥发提金方法,通过延长高温-降温区、缩短低温-中温升温区物料停留时间,利于提高金的挥发率,同时提高氯化钙的有效利用率。(The invention discloses a method for extracting gold by chlorination and volatilization of roasted cyanided tailings, which comprises the following steps of selecting an ore sample, wherein the ore sample is from cyanided tailings obtained after gold fine roasting, acid leaching, cyaniding, dehydrating and drying, and contains 15.08% of water, 6.25g/t of gold, 10.10g/t of silver, 1.6% of sulfur and 33% of iron; adding a chlorinating agent, water and a binder into the cyanidation tailings in proportion, and uniformly mixing; pelletizing by a pelletizer at the temperature of 1000-1200 ℃ for 2 h; drying the green pellets in a drying oven to obtain green pellets, and roasting the green pellets in a muffle furnace at the oxidizing atmosphere of 1100 ℃ for 2 hours at high temperature; placing into a rotary kiln, and roasting for 150min under the condition of continuously heating and cooling at 800-1150-950 ℃; and (5) cooling and then determining the contents of gold and silver. The method for extracting gold by chlorination and volatilization of the roasted cyanidation tailings prolongs the high-temperature-cooling zone and shortens the material retention time in the low-temperature-medium-temperature heating zone, thereby being beneficial to improving the volatilization rate of gold and simultaneously improving the effective utilization rate of calcium chloride.)

1. A method for extracting gold by chloridizing and volatilizing roasted cyanidation tailings is characterized by comprising the following steps: the method comprises the following steps:

the first step, ore dressing, wherein the ore sample is from cyanidation tailings obtained after gold fine roasting, acid leaching, cyanidation, dehydration and drying, and contains 15.08% of water, 6.25g/t of gold, 10.10g/t of silver, 1.6% of sulfur and 33% of iron;

secondly, adding a chlorinating agent, water and a binder into the cyanidation tailings in proportion, and uniformly mixing; pelletizing by a pelletizer at the temperature of 1000-1200 ℃ for 2 h;

thirdly, drying the raw balls in a drying box to obtain raw balls, and placing the raw balls in a muffle furnace to be roasted for 2 hours at the high temperature of 1100 ℃ in an oxidizing atmosphere;

fourthly, placing the mixture into a rotary kiln, and roasting for 150min under the condition of continuously heating and cooling at 800-1150-950 ℃; and (5) cooling and then determining the contents of gold and silver.

2. The method for chloridizing, volatilizing and extracting gold from the roasted cyanided tailings according to claim 1, which is characterized by comprising the following steps: in the second step, the binder is 5% NaCl, and the mixture is roasted at a high temperature of 1100 ℃ for 120 min.

3. The method for chloridizing, volatilizing and extracting gold from the roasted cyanided tailings according to claim 1, which is characterized by comprising the following steps: in the second step, the binder is 3% NaCl +2% CaCl₂Roasting at 1100 deg.C for 120min with the addition of a combined chlorinating agent.

4. The method for chloridizing, volatilizing and extracting gold from the roasted cyanided tailings according to claim 1, which is characterized by comprising the following steps: in the third step, the green pellets are pre-screened by a roller screen, dried by a chain grate and then screened by a vibrating screen.

5. The method for chloridizing, volatilizing and extracting gold from the roasted cyanided tailings according to claim 4, which is characterized by comprising the following steps: screening by a vibrating screen with the size of 14mm, 12mm, 10mm and 8mm to obtain five grades of green balls with the size of +14mm, -14mm to +12, -12 to +10mm, -10 to +8mm and-8 mm.

Technical Field

The invention belongs to the technical field of gold extraction processes, and particularly relates to a method for extracting gold by chlorination and volatilization of roasting and cyaniding tailings.

Background

The discharge amount of tailings of gold mines in China is about 2000 million tons every year, most of the gold concentrate cyanidation plants in China adopt flotation, the roasted cyanidation slag often contains valuable metal elements such as high-grade gold, silver, copper, lead, zinc and the like, and because the cyanogen slag has fine granularity and serious argillization, the gold and the silver are embedded in or wrapped by iron minerals and gangue in a micro-fine manner, the gold cannot be effectively recovered by adopting a conventional method, and the method can only be used for producing building materials, and waste stockpiling or landfill. The high-temperature chlorination volatilization utilizes the characteristics that metal chlorides are generally low in boiling point, easy to volatilize and easy to decompose at high temperature, and the like, and utilizes the action of a chlorinating agent to enable valuable metals to form chlorides to volatilize and enter flue gas for recovery, and gangue still remains in tailings. At the temperature of more than 800 ℃, some metals such as tin, lead, gallium, copper, zinc, gold, silver and the like and sulfides and oxides thereof can generate volatile metal chlorides with the chlorinating agent in the presence of the chlorinating agent. Plum schroc and the like research the chlorination volatilization recovery of valuable metals such as tin, lead, gallium and the like in the tin-containing tailings, and a good recovery effect is obtained. The high-temperature chlorination volatilization extraction of gold is generally considered to be that a chlorinating agent is decomposed into chlorine gas and hydrogen chloride gas at high temperature, and the chlorine gas and the hydrogen chloride gas coordinate with gold of hexagonal crystals to form volatile chloride.

The industrial application research of the chlorination volatilization in the aspect of gold extraction in the roasting cyanidation tailings is less, and no mature gold extraction method exists at present.

Disclosure of Invention

The invention aims to provide a method for extracting gold by chlorination and volatilization of roasted cyanidation tailings, which can completely solve the defects of the prior art.

The research is carried out by combining field production debugging aiming at the roasting and cyaniding tailing chlorination volatilization gold extraction process, and the influence of factors such as roasting temperature, roasting time, granulation mode, pelletizing granularity, roasting atmosphere, rotary kiln roasting temperature field and the like on the gold volatilization rate is systematically investigated. The results show that the roasting temperature, time and roasting atmosphere are main influencing factors, the temperature field in the rotary kiln at the production site is divided into a feeding low-temperature heating area, a medium-temperature-high-temperature calcium chloride decomposition area, a high-temperature chlorination volatilization main reaction area and a cooling discharge area, the decomposition temperature of calcium chloride is 800 ℃, and 26.66 percent of CaCl is contained₂Decomposition, 1150 ℃ is the main volatilization temperature of gold, and 74.63% of gold is volatilized.

Therefore, the invention is realized by the following technical scheme: a method for extracting gold by chlorination and volatilization of roasted cyanided tailings comprises the following steps:

the first step, ore dressing, wherein the ore sample is from cyanidation tailings obtained after gold fine roasting, acid leaching, cyanidation, dehydration and drying, and contains 15.08% of water, 6.25g/t of gold, 10.10g/t of silver, 1.6% of sulfur and 33% of iron;

secondly, adding a chlorinating agent, water and a binder into the cyanidation tailings in proportion, and uniformly mixing; pelletizing by a pelletizer at the temperature of 1000-1200 ℃ for 2 h;

thirdly, drying the raw balls in a drying box to obtain raw balls, and placing the raw balls in a muffle furnace to be roasted for 2 hours at the high temperature of 1100 ℃ in an oxidizing atmosphere;

fourthly, placing the mixture into a rotary kiln, and roasting for 150min under the condition of continuously heating and cooling at 800-1150-950 ℃; and (5) cooling and then determining the contents of gold and silver.

In a preferred embodiment, the second step is carried out by baking the binder with 5% NaCl at 1100 deg.C for 120 min.

As one of the preferable modes, in the second step, the binder is 3% NaCl +2% CaCl₂Roasting at 1100 deg.C for 120min with the addition of a combined chlorinating agent.

In the third step, the green pellets are pre-screened by a roller screen, dried by a grate and then screened by a vibrating screen.

Further preferably: screening by a vibrating screen with the size of 14mm, 12mm, 10mm and 8mm to obtain five grades of green balls with the size of +14mm, -14mm to +12, -12 to +10mm, -10 to +8mm and-8 mm.

Compared with the prior art, the invention has the beneficial effects that: the method for extracting gold by chlorination and volatilization of the roasted cyanidation tailings prolongs the high-temperature-cooling zone and shortens the material retention time in the low-temperature-medium-temperature heating zone, thereby being beneficial to improving the volatilization rate of gold and simultaneously improving the effective utilization rate of calcium chloride.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.